The present invention generally relates to tape cassettes, and more particularly to a tape cassette provided with a lid which closes to protect a tape extending along the front of a cassette case when the tape cassette is not used, and an improved mechanism for maintaining the lid in the closed state and open state.
Presently, video signal recording and/or reproducing apparatuses using tape cassettes are reduced to practical use on the world-wide basis. As types of these recording and/or reproducing apparatuses using tape cassettes, two or three standardized types of apparatuses presently exist world-widely. There is no interchangeability between apparatuses of different standards, however, the interchangeability exists between apparatuses adopting the same standard. Accordingly, a tape cassette recorded by one recording and/or reproducing apparatus can be reproduced by another recording and/or reproducing apparatus of the same standard. Hence, in order to ensure the interchangeability between different recording and/or reproducing apparatuses manufactured by different manufacturers so as to perform recording and/or reproduction, a standardization is established with respect to formats of the tape cassette and the recording and/or reproducing apparatus. That is, the above formats are standardized for each standard, and a standard type tape cassette and a standard type recording and/or reproducing apparatus are respectively manufactured and marketed.
Recently, a problem of much importance involves the realization of a downsized recording and/or reproducing apparatus main body. This is to develop a more compact portable type recording and/or reproducing apparatus, and, for example, to realize such an equipment that a recording apparatus is unitarily built into a television camera.
In this regard, an exceedingly downsized tape cassette was proposed in a U.S. Patent Application Ser. No. 339,675 filed Jan. 15, 1982 (now U.S. Pat. No. 4,494,161) entitled "TAPE CASSETTE" in which the assignee is the same as that of the present application, and this downsized tape cassette is now reduced to practice. When using this proposed tape cassette with respect to the standard type recording and/or reproducing apparatus, this tape cassette is used in a state accommodated within a tape cassette adapter having an external form and size identical to those of the standard type tape cassette. On the other hand, when using this proposed tape cassette with respect to a compact type recording and/or reproducing apparatus, this tape cassette is used in a state as it is without the tape cassette adapter.
The above proposed tape cassette which has been reduced to practice, comprises a lid which closes to protect a tape extending along the front of a cassette case when the tape cassette is not used, and opens to a position not interfering with the drawing of tape out from the cassette case when the tape cassette is used, wherein the lid is of a design comprising a mechanism for maintaining the lid in the closed state and the open state. According to this tape cassette, when accommodating the tape cassette into the tape cassette adapter prior to being used with respect to the standard type recording and/or reproducing apparatus, there is no need to hold the lid in the open state by a finger because the lid is maintained in the open state once the lid is opened. Hence, the tape cassette can easily be accommodated within the tape cassette adapter in a state where the lid is in the open state, and further, the tape can be drawn outside the cassette case with ease.
As will be described hereinafter in conjunction with the drawings, the mechanism for maintaining the lid of the tape cassette in the closed state and the open state comprises a slide rod slidably provided on a side surface of the cassette case in a state making contact with the peripheral surface of the lid at a part in the vicinity of a rotary fulcrum of the lid, and a spring for urging the slide rod towards a direction so as to make contact with the peripheral surface of the lid. However, the above slide rod is simply fitted into a groove open at the side surface of the cassette case, and there was a disadvantage in that the slide rod could easily escape from the groove.
Accordingly, in order to prevent the slide rod from escaping from the groove in the cassette case, a design was tested wherein the groove is shaped as a dovetail groove and the slide rod is shaped to have a trapezoidal cross section. However, if a cassette case having such a design is to be molded from plastic and the dovetail groove is to be formed integrally, the mold must be pulled along the extension of the dovetail groove. On the other hand, holes in the cassette case for supporting hinge pins of the lid extend along a direction perpendicular to the direction in which the mold for forming the dovetail groove is pulled. Therefore, it is impossible to integrally form the dovetail groove and the holes for supporting the hinge pins of the lid simultaneously, when molding the cassette case.
Hence, it becomes necessary to integrally form the dovetail groove when molding the cassette case, and thereafter form the holes for supporting the hinge pins of the lid by an additional process such as a drilling process for drilling the holes. The number of processes required for forming the cassette case increased because of this additional process which was required, and it was troublesome to carry out this additional process to form the holes. Further, errors were introduced in the drilling positions and the like for forming the holes, and accordingly resulted in defective cassette cases. Therefore, there were disadvantages in that the working factor and the production efficiency in manufacturing the cassette case became poor, and the manufacturing cost of the cassette case became high.
Another design was tested wherein the slide rod is connected to the spring. However, the construction of the cassette case became complex according to this design, and the assembling work factor became poor. In addition, there was a disadvantage in that the slide rod could not be completely prevented from escaping from the groove in the cassette case.